首页 > 解决方案 > Dash python:如何用 csv 内容填充 dcc.dropdown?

问题描述

我想在 python 和 Dash 中创建一个网络应用程序。我尝试的第一个是创建一个下拉列表。

我有这些数据:

Date,FS,Total,Used,Mount
2020-01-25-12-00,/dev/hd1/,350,300,/dev/mount1
2020-01-25-18-00,/dev/hd2/,370,320,/dev/mount2
2020-01-26-06-00,/dev/hd3/,395,350,/dev/mount3
2020-01-26-12-00,/dev/hd1/,350,300,/dev/mount1
2020-01-26-18-00,/dev/hd2/,370,320,/dev/mount2
2020-01-27-06-00,/dev/hd3/,395,350,/dev/mount3
2020-01-27-12-00,/dev/hd1/,350,300,/dev/mount1
2020-01-27-18-00,/dev/hd2/,370,320,/dev/mount2
2020-01-28-06-00,/dev/hd3/,395,350,/dev/mount3
2020-01-28-12-00,/dev/hd1/,350,300,/dev/mount1
2020-01-28-18-00,/dev/hd2/,370,320,/dev/mount2
2020-01-29-06-00,/dev/hd3/,395,350,/dev/mount3

我想用我的 CSV 的所有 FS 创建一个下拉列表。我尝试这样做:

import dash
import dash_core_components as dcc
import dash_html_components as html
import sys
import os
import pandas as pd 

app = dash.Dash


df = pd.read_csv('/xxx/xxx/xxx/xxx/xxx/xxx/data.txt')

test = df['FS'].unique()

dcc.Dropdown(
    options=[test],
    searchable=False
)  

if __name__ == '__main__':
    app.run_server(debug=True)

但输出是

Traceback (most recent call last):
  File "./import dash.py", line 25, in <module>
    app.run_server(debug=True)
TypeError: run_server() missing 1 required positional argument: 'self'

你能告诉我为什么吗 ?

标签: pythondropdownplotly-dash

解决方案


您的代码中存在一些问题:

  1. 您必须为破折号应用程序指定一个名称,例如app = dash.Dash('app_name')

  2. 您的 csv 有混合分隔符(,在标题和;元组中)

  3. 下拉选项语法是{'label: 'somelabel', 'value':'somevalue'},例如(参考下拉示例和参考

options=[
        {'label': 'New York City', 'value': 'NYC'},
        {'label': 'Montreal', 'value': 'MTL'},
        {'label': 'San Francisco', 'value': 'SF'}
    ],
  1. 您必须将组件分配给app.layout

总结一下:

import dash
import dash_core_components as dcc
import dash_html_components as html
import sys
import os
import pandas as pd 


app = dash.Dash('app_name')

df = pd.read_csv('/xxx/xxx/xxx/xxx/xxx/xxx/data.txt')

test = df['FS'].unique()
options = [{'label': t, 'value': t} for t in test]

app.layout = dcc.Dropdown(
    options=options,
    searchable=False
    )

if __name__ == '__main__':
    app.run_server(debug=True)


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